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Seriously, that's four of the first 9 posts into this thread removed for being just moans and therefore totally off topic. There's a note at the top of the thread about this, and countless reminders have been posted by the team, it's to the point where those continually ignoring all this, and just posting whatever they like in this thread must be doing so deliberately which shows zero respect for others in the community. So, next step will be to tighten up again and start blocking people from posting in here without further warnings.

As usual there are different ways of looking at this. A few things: 1) We have been able to successfully trace the end of one cold snap in mid January to plot (in advance) the development of the next (albeit its not the 1991 redux one might hope for). That has been possible, through some collective effort and different methodologies converging. As a practical community exercise that illustrates one of the benefits of being a member of a forum such as this - and far too often it gets obscured and not acknowledged as much as it should. The rollercoaster element might provide the excitement when things look good, but it also can serve to detract the community positives when the solutions on offer do not appeal to the eye of the audience 2) Participating in the regional thread over the coming days will make the most of the snow opportunities there are to come, so it need not be a let down at all. We cannot make it snow. let alone everywhere, and not to desired quantities, but its still possible to make the most of what might come. Otherwise all the chasing since mid January (for those who managed to see snow) has no reward away from the computer. So best head out take pics and enjoy it while it is here and then report back 3) GP has posted in the technical thread and it makes complete sense as reflected by NWP. I spoke the other day about the need for the tropical signal (the nucleus for downstream amplification) to work its way through to the extra tropics and only then the full amplification potential downstream can be assessed. Clearly from the downstream pattern that has come into model consensus today, the amplification potential suggested by the Pacific forcing is not apparent to that extent and I had been thinking yesterday evening there must be (again!) a destructive I/O signal not allowing it to fulfil expectations. In data terms it doesn't seem much at all, but in terms of ripples in a pond stemming from the smallest pebbles, they nevertheless spread far and wide. The timelines I have referred to are clearly set to be at the longest end of the envelope, but then estimations can only be as good as the last data set. This certainly doesn't debunk the initial thinking, but it does mean we will not get the more seamless movement from one cold evolution (Scandi High) to the next that seemed possible - and it explains why the retrogression signal (which had been responding to in line with expectations) has faded. If anyone thinks it should be due, I will accept any responsibility for heightening any expectations by speaking of converging signals producing "the icing on the cake" but then I will also stick to the fact that this had been quite feasibly reasoned (and believe the fullness of time will show that) 4) The interpretation to take from all this in GSDM terms suggests that the Global Wind Oscillation orbit will be much shallower amplitude than anticipated until the destructive interference from the tropics diminishes. I find it very frustrating that such a compelling tropical and extra tropical amplification signal has been diluted and delayed - having coming so far so well. Hand in hand with a split vortex solution rather than a displacement, some of those highly appealing ensemble solutions up to yesterday would not have stayed in the virtual world.... 5) However there is still the compelling real time signal spoken of in detail previously of rapidly rising angular momentum tendency. The MJO signal might have had an unwanted intervention, but it has not gone away. Lagged by the tropical glitch, rising frictional torque and then mountain torque still cues up the expected amplification - but destined for a cold finale to winter and usher into Spring. Whether the whole audience welcomes that or not is completely subjective of course. 6) Finally, what we can deduce from all this is yet another proof exercise of what I often repeat. The teleconnections do work, but they do not always evolve to optimise the most desired result. But then that has always been the point - this forum has a natural bias, the science of meteorology has no bias.

A dramatic change from the ECM, main block is over Greenland on the 12hrs run , on the 00hrs this was over Canada.

Conclusion from the comments of some: 'Blink and you'll miss it' cold snap - Suggests no longer than 2 or 3 days. Snow only to hills Spring warmth within days What the models actually show: 5 day cold spell, with frost, ice, cold easterly winds and snow opportunities for most Turning less cold next week and possibly milder later next week, but anything that far ahead is always uncertain Rather confusing!

Premature Atlantication? Indeed though, a continuing pattern through this winter, we can comment on the output but any certainty of outcome is still up in the air.

One final post before bed. I am going to eat some humble pie and give huge praise to Tamara because I am afterall fair. I have been looking at some previous model runs and posts on this thread for the period 29th Jan. Look at what the GFS was predicting for tomorrow on the 29th Jan. This is what Tamara said on the 29th Jan. "However, the upstream jet, is set to decelerate rapidly as pressure rises over the Pacific and re-build the Aleutian Ridge. In the Atlantic sector, the retrogression of the pattern will tend to angle the Jetstream more NW/SE and, conceivably, enable build of pressure over Scandinavia. With time, as the disrupting trough gets separated from the Canadian lobe of vortex, downstream amplification from the Pacific sector becomes possible at the same time as the wave 2 response is activated by rising pressure over Scandinavia to work on the vortex in tandem with the Aleutian Ridge. It is key at this point that the vortex is sufficiently weakened to allow the bleeding of secondary systems to be cut off from the Canadian lobe - and hence terminate the thermal gradient." https://www.netweather.tv/forum/topic/87058-model-output-discussion-25th-jan-the-final-third-of-winter-beckons/?page=12#comment-3534098 Astonishing forecast and I cannot give her enough praise.

A fresh new model thread as we start a cold spell. We've made a change this morning, and that is to start a new model tweet thread. The reason for this change is that a tweets are, by their nature brief, which in turn can leave them open to multiple interpretations, which in the fast-moving model thread can mean a lot of reaction to misinterpretations which pulls the whole thing off on a tangent. So please don't post tweets into this thread - keep them to the new thread. We've also started another new thread this week, and that's the In depth (chilled out) model thread, for those who want a slower paced look at the models. Cross-posting to this and the new thread is fine, the best route to doing this is to use the multiquote button (the + sign bottom left of the post), then when you go to post your new post, you'll see a button bottom right allowing you to quote the post & copy it over. If you're unsure where to find the models, head over to the Netweather Charts and Data homepage, where you'll have access to all the main ones - including our in house NetWx models, the SR hires version is particularly handy when it comes to forecasting snow showers at shorter range. As ever, please keep this thread to model discussion only - and that does mean actually discussing the output, not just moaning about it. If you want to moan, ramp, or even moan about ramps, please head over to the model banter thread:

I get some are disappointed with how long the cold may last but some will have a fun few days. This snow detail can change but if you get some enjoy.

The amount of retrogression of the Azores/Iberian trough and the positioning of any Atlantic/Euro blocking is still to be firmed up during next week.What energy there is in the Atlantic jet is well south with nothing to prevent further ridging of the block.-indeed all modeling showing hints of this as soon as day 6 The T144 modeled jet The 3 at T144hrs. with the main bulk of the vortex on the move towards the Siberian side then the window is there for further development of height rises to our north west -GEFs mean at t240hrs It looks like an evolving pattern which will take some days to become clear but as the Atlantic remains so quiet then some form of blocking remains the longer term likely pattern.

So..the Gfs 12z shows a very cold Easterly with snow showers during the next 3 or 4 days which is wonderful and then we flirt with an Arctic airmass towards the end of next week..something to build on!

Just to attempt to bring a sense of reality back to this thread to all those who appear unable to control their emotions because we aren't going to get a Beast From The East style Easterly. Despite what an alien may think if they had just arrived from outer space and started reading the last few pages of this forum, I am sorry to burst some bubbles but a 'proper' snowy Easterly was NEVER actually forecast by anybody of any standing here simply because, other than a few wayward Op runs, it never showed up on the charts. It was ALWAYS an outside chance and so it proved to be correct. It would appear that some exuberance and excitement exhibited by those of us who actually enjoy the chase when there is a genuine opportunity of a snowy spell has been mistaken for some sort of set in stone 100% forecast. Nope we were just getting excited by the possibility of. some people evidently need to be able to distinguish between the two. Our alien will now read this post and will no doubt think there is no cold spell at all arriving! So imagine his confusion when the next thing he does is go on to view the charts. Why? because we do have an Easterly on the way and a half decent one at that as well. He would then be no doubt further perplexed as he scrawled through the charts trying to find this searing plume sourced from the scorched deserts of Africa that many speak of... Of course we are all a bit disappointed that the easterly does not look like being as good as it could have do but conversely it could have not verified at all (most don't make it over all the hurdles and through all the hoops required to get to a winter Easterly). Let's see what occurs instead of writing it off before it is even here FGS. So much left to happen yet, best model watching for a long time.

Very briefly as I'm not at home for all the desktop links. An animation of the 200 hPa stream function (jet stream level) of the different phases of the MJO. The little phase 'clock' (top right) shows the heights building over eastern Canada and Greenland as the 'hand' passes through phase 8 -1. http://envam1.env.uea.ac.uk/mjo.html That's a very rough interpretation as it is not a fixed entity - depends on season and amplitude as well as Kelvin waves and tropical cyclone activity.

Not sure the upstream teleconnections are as favourable as being advertised by RMM MJO plots. 200hPa velocity potential is much further east than would be considered for phase 8, and threatening an Indian Ocean evolution: That's more phase 1 territory which is no where near as favourable for high latitude blocking. Factor in the displacement of the upper vortex towards Siberia and you get a signal for Euro ridging as per NWP extended means. Very similar to the mid / late November episode. That's not to dismiss the text book spike in tendency in angular momentum that has occurred on the back of the evolution of the tropical wave through the Pacific, but my take on that would be for more of a hit to the stratospheric vortex at the end of the month and more robust blocking signal to the NE / N at this time, and into early March, although for the lowland snow chasers that's too late I appreciate.

What kind of Atlantic jet stream pattern is this? Answer: one that you may not have seen too often before! (where has the jet gone?) No wonder it appears that the pattern is stagnant and time has stopped still.

Using a bit of reverse psychology I'm really looking forward to the mild spell the Gfs 00z is showing next week..i hope nothing goes wrong..Sidney might even come out of hibernation

Not had chance to read the last page or two but just some comments from me using my old trusty (usually!) 500 mb anomaly charts for beyond the spell of easterly weather into this weekend. Not too clear in my view but have a read and see what you think. Net Wx 6-14 day outlook on wed 8 feb 2017.doc

Evening- Little time to post really today- sometimes life calls - So, 'the blinks & you will miss' it 5 day cold spell will be apon us tomorrow- Its certainly worthwhile noting that this whole winter has been punctuated by average MLB's then just 5 days later post SSW we have a tropospheric response & acute MJO delivering a HLB scandi High- the longivity of the cold spell is then cut short perhaps, by the quick recovery of the zonal wind- but also by those 'unknown unknowns' whereby these days whenever we get a good Easterly the azores high just wants to leap NE & kill the flow, where as yesteryear the atlantic would dive SE cutting off that ridge- I guess we probably will never know - So post xmas I was posting the strat zonal winds on a regular basis & using them to promote the early indications that a SSW would develop- since then & on the run in to the cold spell that link had gone off the pad a little bit- well its certainly back on it tonight with a very important update that indicates a further SSW is forecast for the 21st of Feb with the deceleration date the 13th- so spanning 8 or so days we will go from the recovery peak of 30M/S to negative -5M/S ( approx )- this will probably be a wave 1 'final warming' The CFS has been modelling this day after day for late Feb early march ( purple lines ) & the GFS is in full support s - once again, whilst there could be the usual lagged propergation of 10 days - the troposheric response around 16-18 Feb could replicate something very similar or better to what we have now- with a decent HLB ( poss 2) located nearer Greenland- whilst we possibly dont get a full vortex split the net result may well be the displaced vortex in to russia / Scandi - With a final warming so late & with a nice negative anomaly around the zonal mean the likleyhoood of a fast rebound is a lot lower with the potential for a 'broken' vortex all the wayaround until next winter- just like this year. The reprecussions for March are a below average month should be predicted. Back closer to the hear & now - whilst the next 7-10 days feel like they have available energy to keep the blocking & -AO at bay, post that should be an almost 'perfect period' for MLB blocking... & of course potential for quick tropospheric blocking as well. So for me, we get over this cold spell & around the 16th-18th we are confronted by a quick fire SSW -- The modelling impacts on the AO are very profound with their negative manifestations-- some ensemble suites run it down to -6!!! So is it a given- no.... however the next cold spell is forecast around the 16-18th... best steve PS dont be surprised if this 'huge' milder blip around 144 is smoothed into minimal inpacts ..

A real wintry flavour to the Gfs 18z for the next 4 days with snow showers, ice and moderate night frosts with a bitter Ely flow..proper winter!

We don't get a great view on the UKMO T168hrs but theres enough there to suggest it has a Greenland high at that timeframe, because we know where the high was at T144hrs then it moves this further east. The issue at present is some of that shortwave energy cutting se towards Iberia, we want to see that happen and shortwave energy to detach from the troughing upstream but at least we're seeing signs that pressure will rise to the nw.

Those hoping for a gander among the daffodils next week may need to consider taking along a coat (and maybe a scarf, gloves and hat too).

-8 to -10 uppers covering all of the UK. Not confined to Scotland and the North East coast at all.

Yes and one has to say that even though the mother of all cold pools has not hit the UK, a Strong Scandi high has developed and a cold pool is due to hit this weekend so synoptically not far from the mark. And I would not rule out a Greenland block yet. Whether it is strong enough to send a northerly to the UK remains to be seen but yet again synoptically @Tamara can herald this a success for the closeness of the suggested pattern. I don't ever remember her touting a strong Atlantic and we have certainly not seen that. In meridional flows there is always an element of polar temps dropping south but in order for this to happen there is an equal and opposite element of transfer of warm temp anomalies transported north. And for a small country such as the UK we can always miss one and get the other or in this case get both. And isn't the output a tease with the block retrogressing over Iceland and then retreating back to Europe?

1 hour ago, snowflakey said: Agree with you 100%,the block looks to strong for it to just slip away, I know the cross model out puts are saying a different thing, but I've still got confidence in the HP to be a bit more unpredictable The problem is that we have a deep cold pool over Northern Canada which is stubbornly remaining there. This will continue throwing out cold air outbreaks into the NW Atlantic. Until you remove that cold pool it doesn't matter what those background signals are... the block will struggle to build over Greenland as a result. Saying that though I believe there are two factors that I believe are comprimising this winter: - The QBO pattern. - North Atlantic cold blob. High pressure seems to be sticking to Central Europe like a magnet this winter. We seem to be falling into the same trap as what we did at the start of the winter, we keep saying the background signals favour cold therefore it will be cold. This however is not the case, often it is just observing where the cold and warm areas are in the relevant parts of the world within a reliable timeframe. In the reliable timeframe unfortunately we have cold pools in the wrong place (when moving away from the UK!). Sometimes the teleconnections can be strong enough to overwhelm the formation of the PV around the NW Atlantic but not at this point! Edited 1 hour ago by Quicksilver1989 --------------------------------------------------------------------------------------------- @Quicksilver1989, couldn't quote from the old thread so did a copy and paste. What you said has merit with regards to the specific context of a Greenland high. But @Bring Back1962-63 is completely correct in terms of the cold blocking over Europe being consistently underestimated for weeks on end. Using Warsaw as an example, looking at the 7-10 day range and even closer, milder air has been forecast to make inroads. However this has not eventuated. A forecast 10 days out of a 7 degree maximum has turned out to be a -1 maximum and so on. This is easy to miss if you’re only looking at UK forecasts. Now this difference hasn’t created a snowmageddon for the UK but it has made a difference at times, the recent ice day in the South East was a result of the cold continental feed stubbornly hanging on when it had been forecast to depart. In the narrow context of the UK weather I can’t be sure what would happen, but my own thoughts chime with @Bring Back1962-63 and others, that the cold over Europe will hang on for much longer than forecast and the eventual outcome will be rather different than modelled.

Tomasz Schafernaker not particularly excited by the upcoming cold 'snap' other than some flurries, so lets see if we can be more enthusiastic than Tom re: snowfall? T+72 fax chart shows a developing 'warm' front moving west from N Germany and Denmark toward the UK, IMO this marks a plume of moisture, rather than warmth in the literal sense, being drawn NW out of central Europe and, with lift from the 500mb trough and surface low moving east over the N Sea will probably enhance snow showers Friday PM and Friday night into Saturday morning t+72 fax and PWAT (Precipitable Water) A look at forecast skew t for Essex Friday PM shows increase in moisture in lower layer (more snowfall) between T+72 and T+82 i.e. where dew point line (left) is merged with temp line (right) the air is saturated ... notice thicker layer of moisture at T+84 between 950 and 800 hPa. This fairly representative for eastern coastal counties of England T850s down to -11C across England Friday night and not often we see partial thicknesses (850-1000hPa) 127 gpdm 500mb trough providing plenty of lift Friday night So looks like there is the dynmaincs there to pep the snow showers Friday night and probably through Saturday too as that trough and increased moisture moves in.

A new thread, for posting and discussing tweets about the forecast models currently. Please only post tweets in this thread, not the main model or banter threads. The reason for this change is that a tweets are, by their nature brief, which in turn can leave them open to multiple interpretations, which in the fast-moving model thread can mean a lot of reaction to misinterpretations which pulls the whole thing off on a tangent.

First post of evening focusing on models other than GFS for the next few days, scattered light sleet and snow showers towards eastern parts Thursday and Friday. But perhaps snow showers pepping up and moving inland across E England Friday night and spreading well inland toward the west on Saturday as upper low on near continent and troughing in surface isobars increases lift looking at 12z UKMET-G 500mb vorticity 12z EC similar Friday night shouldn't be a problem for snow to lower elevations but during Saturday dew points becoming marginal, so could be a messy mix of sleet and snow inland and probably rain on the east coast.

It was less than a week ago when the models didn't indicate any snow and neither did the met office but things have changed and now we have our cold showery easterly with an increasing chance of snow..it's turned into a nice bonus from what was looking like a benign nondescript spell..enjoy it I say.

You have to laugh. North African plume now showing and just in case you're all wondering where the gritters are, well, all the salt is being rubbed into our wounds as yet again the north east US get the frigid cold spoils. You just couldn't make it up. Better make the most of the next few days.

Interestingly for coldies there are quite a few cold looking GEFS 6z perturbations in the extended range with Nly / NEly outbreaks..fingers crossed!

He doesn't say one last cold snap. That would be a foolish thing to say at this stage.

I'm not sure where this severe cold was forecast? Theres opportunities for cold and snow during the next few weeks but the easterly doesn't have a lobe of the PV underneath it to provide that depth of cold. Unfortunately easterlies seem to get expectations that are rarely met, it would be great to see one of those 5 star ones again but we are where we are. In the context of UK winters 4 to 5 days below average with some snow and frost is quite a success and there maybe better to come later after that less cold interlude.

This thread is looking rather lonely and the other one, I hope, has reached its nadir today. People are fretting about the Scandinavian block sinking but have they really looked at why that is being modelled. An animation... Where's the Atlantic in the picture? It is not sinking because of a raging Atlantic jet stream riding over the top - it is being sunk by a huge chunk of Siberian vortex putting pressure on it! What happens when you sit on a big round beanbag; it squishes out to the sides ...on one side is Greenland. As @MattHugo says in the model thread, give it time and have a bit of patience.

A most curious outcome indeed and quite an adjustment from the previous run. Enough to encourage happier dreams tonight as I leave it there for now. Let's keep shifting the broad scale pattern west tomorrow...please!

This is exactly the conclusion I formed some time ago. There's no doubt that they have an effect but the correlations between all these measures or at least current understanding of them seems to be limited. I very much admire Tamara et al who are willing to share there knowledge as our understanding of the interplays between them develops. They are often the target of some posters when things don't go to plan but I think we need to accept that our understanding and hence usefulness of these measures In terms of forecasting rather than hind-casting will improve over time. pioneering is how I see this area right now and I have great respect to those who are willing to share their musings publicly.

Sry no spring this weekend

I don't know whether to admire those who study teleconnections or feel sorry for them lol. So many variables and the smallest of these can cause huge flips in the forecast. Seems almost like a thankless task.

Well, i'm in Cornwall right now, today was a beautiful sunny day, worthy of spring. We drive back on friday evening and we could be seeing this on saturday- Now that would be a great ending to a great week

Finally some good progress from ECM with the pattern adjusted a good way west. Heights becoming low across Scandi for a change! Cold air resource getting recharged not far to our east. Chiono's NE import scenario can be envisioned going forward, spanners not withstanding...

Much more HP and dry continental air influence from ECM this evening so retaining cold nights while days could be very pleasant in light winds. As less cold interludes go it would be very tolerable...

Eat that - Indian Ocean

Be careful when looking at composites for MJO phasing. Joe Bastardi tweeted something yesterday - February high amplitude phase 8 was rare in the record. That made me have a look at the years and do my own composites. The years are 2001 - 1999 - 1990 and 1988. I've include 2008 as the CHI progression was much higher amplitude than the OLR one - not sure if that makes an overall difference. The composite reanalysis of the five years for February and March. Composites, by their nature, are a blend of the years involved but could there be a clue in the above as to what to expect in a few weeks time. https://www.esrl.noaa.gov/psd/cgi-bin/data/composites/printpage.pl https://www.esrl.noaa.gov/psd/data/climateindices/index.html

I'm not trying to speak against the facts about what the models are showing. However, I wouldn't be surprised with a different scenario showing its hands after the weekend. Still plenty of time for corrections and alterations that could easily place us in the firing line for a reload. One very tiny difference could occur within the orientation of these southerly winds. If we end up with a less intense low towards Iberia and it doesn't sink adjacent to Morocco, then there's no route for the African heights and winds to be scooped up. Not only that, the high pressure could well end up orientated differently and allow a less SEly component and more cold flooding into the Balkans. That would then leave us God knows where. A very interesting model watching period coming up I feel.

A bit more time now and have been able to look at month specifics - the 1988 event is probably the closest to what is anticipated in the forecast - the other years had different timing and little foibles of amplitude and direction. Forecast. Feb '88 The composites for February and March 1988. The ERA reanalysis for 15th February onwards as it's interesting to see what weather patterns went with it. http://www.meteociel.fr/modeles/archives/archives.php?day=15&month=2&hour=0&year=1988&map=0&region=nh&mode=2&type=era Only part of the story and events in the stratosphere may completely change the picture anyway. @nick sussex mostly solid Nina.

It's snowing!!!! Probably stopped by now!

Looks very light and patchy to me...more the kitten from the east than the beast.

Yes true, I am always, even when working, suspicious of lows anywhere south of the UK, unless the Channel faster moving variety, and milder air being brought back from the Med area. This happens also even in the Channel ow mentioned above once it starts to slow down/stall over Europe. In many ways for deep cold then the Greenland high and troughing Scandinavia/Europe is preferrable than the much sought after easterly. I actually doubt, provided the northerly creates even minor troughs (which is normally does) that most folk get more occasions of snow with this set up than the easterly type, largely, perhaps, because the former is more frequent than the latter? Or am I totally up the wrong snowman?

Super computers,what is the point

My round up of where we are. Today until Sunday a deepish cold spell with 850's of -5/-11 is a fairly deep spell albeit 5 days long with snow showers for some perhaps significant snow for the North York moors/dales at times. Sunday-Wed milder users but feeling raw in asoutheast wind and low dew points. After that I'm sorry I just don't buy or agree with mild southerlies dominating, the models are in complete limbo and haven't got a clue of what to do, granted the mjo signal isn't been picked up at the minute, I'm not sure why, because it's a more amplified mjo for many months, perhaps it's a lag, also the strat warming should at least propergate down more than is been shown at the min, this easterly is trop led in my opinion not strat led. I think once we have this wkend out the way we all should see a clearer more definitive path of where we're heading.

Remember a couple of weeks ago when all the models (apart from ukmo as it did not go out that far) were persistently showing long draw south westerlies at day 7 onwards? I need say no more.

Ive enjoyed this past few weeks for the string of deep frosts & frozen lakes- culminating in an ice day the other Thurs- Looking forward to the weekend- I bet somewhere like bluebell/wrotham/Meopham will end up with a few CMs fri/Sat... S